Method of and apparatus for treating solutions and products



METHOD 0F AND APPARATUS FOR TREATING SOLUTIONS AND PRODUCTS Filed June 15, 1927 Patented June l2, 1928.

UNITED STATES PATENT OFFICE.

WILLIAM B. JOHNSTON AND ALEXIS W. BEEN, OI NEW YORK, N. Y., ABBIGNOBB TO THE N AUGATUCK CHEMICAL COMPANY, OF NAUGATUCK, CONNECTICUT, A CORPORA- TION OF CONNECTICUT.

METHOD 0F AND APiPABATUB FOB TEEATING SOLUTIONS AND PRODUCTS.

Application lcd June 15, 1921. Berial No. 199,112.

This invention relates to a method of and apparatus for treating solutions of material and to the product, and is more particularly concerned with the recovery of plastic, gummy or amorphous materials from their solutions.

Difiiculty is had in the recovery of certain plastic, amorphous or gummy materials from solution, since owing to the character of the materials, the solvent cannot be readily and completely eliminated. 111 certain cases the driving off of the solvent can be assisted to some extent b steam distillation, but even then it is di cult to entirely remove the solvent and in many cases the product is then also contaminated by a certain amount of moisture from the steam. 'Moreover, in the arts it is frequently desirable to obtain materials of the character specified in a powdered or finely divided form, and owing to their physical characteristics, this cannot be readily done if they are first recovered from solution in compact and undivided form.

An objyt of our invention is to rovide a process by which a plastic, amor ous or gummy material ma be recovere from a solution thereof wit complete or nearly complete elimination of the solvent. Another object is to provide a recess by which the solvent can be removed with the aid of steam without contamination of the product by moisture. Still another object is to provide a method for recovering a plastic, amor hous or gummy material from a solution t ereof in a friable expanded cellular mass which can be easily crushed when the material is desired in a powdered or finely divided condition. Further objects are to provide an apparatus for carrying out the method and to provide a product of the character above s ecified.

The invention broa ly comprises intimately mixing a vaporized agent under pressure with the solution to be dried, and suddenly releasing the pressure. It further comprises intimately mixing a heated seous drying agent under pressure wit a solution of the material to be dried under pressure, extending the mixture into attenuated form while maintaining the ressure and heat, and suddenly releasing the pressure. The invention further comprises the product of the method and an apparatus for carrying out the method.

I "or a detailed disclosure of the nature and objects of the invention reference is had to the accompanying specification and drawing, in which latter:

The figure illustrates one form of an ap aratus for carrying out the method.

eferrmg to the drawing, the numeral 1 represents a pipe for the solution of the plastic or other material, 2 is a pipe or Jacket surrounding the pipe 1 for supplying the heating and vaporizin agent, and 3 is a screw cap adapted to be t readed on to the jacket 2. The screw cap 3 has rigidly connected thereto a nozzle member 4 located opposite the passage 1 and provided with a discharge passage or bore 4 A lock nut 5 threaded on the jacket 2 engages the cap 3 and holds it in a predetermined position whereby the base of the nozzle member 4 can be seated against the forward end 6 of the passage 1 or can be spacedV apart therefrom at a predetermined distance. It is obvious that this spacing can be varied by moving pipe 1 insteadl of nozzle member 4. The ad]oining ends of pi e 1 and nozzle 4 are preferably groun so that an accurate control of the vaporizing agent may be had at this oint.

The path o the solution is indicated at 7 and the path of the vaporizing medium at 8.

In operation the vaporizing medium is introduced into the jacket 2 and run through it until the passage 1 has become heated. Thereupon the solution to be dried is introduced into the passa e 1 under a lesser pressure than that appied to the va orizin medium. With the nozzle member E space apart from the forward end 6 of the passage 1, the vaporizing medium follows t e general course indicated at 8, and comes in contact with and mingles with the stream of solution whose direction of travel is indicated at 7. The mixture of the Vaporizing agent and heated solution is ejected or extru ed through the passa e 4 nozzle. The mixture as it reac es the mouth of the assage 4 issues in the form of a rod or sti lled with small bubbles of the of the vaporizing medium which sometimes ex Vlode with a snap. The solvent in the pastic solution is va orized during the travel of the mixture t rough the p 4. The rod or stick builds up continuous y and may be recovered in lengths or ieces as desired substantially dry and free from solvent and in a form which is readily ulverizable due to its spongy texture and w ich is in a convenient form for further manufacturing operations.

To illustrate the practice of the invention a 60% solution of a polymerized styrol in ethyl benzol or other organic solvent may be employed as the solution of the plastic. Steam under pressure may be employed as the vaporizin medium. The steam is started throug the jacket 2 at say 115 lbs. pressure, and after a brief period to insure the proper heating of the passage 1 and the nozzle 4, the llow of styrol solution is started through the assage 1, and the styrol solution is place under a pressure of -80 lbs. in an desired manner. The styrol solution is thus preheated during ,itsk travel through the passage 1 and, at the time it reaches the end 6 of the passage 1 has acquired substantially the temperature necessary to vaporize the solvent. The steam swirls around in the cap 3 and seeks e ess through the opening between the base o the nozzle 4 and the end 6 of the passage 1. Here it comes in contact with the solution, and mingles therewith and the mixture then issues through thepassage 4' by virtue of the sitive rassure on the steam. During e trave through the passage 4 in the nozzle, the ethyl benzol or'other solvent is substantially completely vaporized, but is entrap d m the styrol in bubbles, `along with t e steam. As soon as the mixture ,issues from the mouth of the assage and the pressure is thus suddenly and entirely released, the bubbles expand and both ethyl benzol and steam escape from the issuing olymerized styrol. The polymerized styro ui ds up continuously at the end of the assage, and assumes the form of a rod or stick of sufficient strength and tenacity to support ,its own weight over some little distance of travel as a result of which it can be broken olf and collected lin stick or rod form. These sticks, being filled with pores and passages due to the sudden escape of solvent and steam, can be readily re uced to a owder by simple grinding. In the manu acture of certain types of articles the crudely broken sticks may be molded directl without first grinding them to a ow r.

While the operation of the method has been illustrated with a solution of polymerized styrol, the invention may be a plied to the treatment of other pol erize plastics or in general to any so utions of ma- :,evaees terials which when dried have sullicient cohesion betweenthe particles thereof to form a continuous stick or rod. The invention appears to be more suitable to solutions of materials in organic solvents which can be removgd by steam distillation.

The steam may be more or less super-heated prior to the introduction into the jacket in which case there will be a lesser opportunity for condensation of water in the stick of plastic with consequent production of material containing less moisture-and which may be made bone dr if desired. Further, the higher the superlleat on the steam the more shredded or sponge-like is the rod of poymerized styrol. From itl-150o F. is su cient superheat for most purposes. It

is desirable to have the passage 4 in the nozzle of suilicient length so that the sol vent will be substantially completely vuporized, but not so long that the plastic will be completely dried within the passage as this tends to reduce the rate of discharge. For treating styrol solutions a passage length of 11/8 in. an a diameter of about .20 in. will give very satisfactory results. In the above specific embodiment the pressures are capable of variation. For the vaporizing medium the available heat must be sufficient to insure vaporization of the solvent. The pessure on the styrol or other solution will dependent of course upon the viscosity of the solution. However, it is necessary that the steam or vaporizing agent be under higher pressure than the styrol or plastic so ution, in order that the latter is not forced into the steam jacket.

It ,is of course understood that variations in nozzle construction and temperatures can also be made without departing from the spirit of the invention. The process may be run in connection with solvent recovery aparatus in order that there may not be a oss of solvent.

Having thus described our invention what we claim and desire to protect by Letters Patent is:

1. A process for removing solvent from solutions of solid materials which comprises intimately mixing a gaseous drying agent under pressure with a solution of the material to be dried, and suddenly releasing the pressure from the mixture.

2. A process for removing solvent from solutions of solid materials which comprises intimately mixing a heated gaseous drying agent under pressure with a heated solution of the material to be dried, extendin the mixture into an attenuated form, an suddenly releasing the pressure.

3. A process for removing solvent from solutions of solid materials which comprises intimately mixing a heated gaseous drying agent under pressure with a heated solution of the material to be dried, extending lll) the mixture into attenuated form while continuing the heating and pressure and suddenly releasing the pressure.

4. A proross for removing solvent from solutions of solid materials whirh romprises preheating said solution, mixing.lr therewith a. vaporlzing medium under pressure, va oriziug.r the solvent in the mixture while sti under pressure, and suddenly releasing the pressure on ihn` mixture.

5. A process for converting solutions of polyiuerized plastics into solid form which comprises preheating a solution of a. plastic, mixilnr a vaporizing medium therewith, distilhng oll the solvent while projecting thc mixture through a constricbed passa and suddenly releasing all pressure at t e und of the passage, whereupon entrapped solvent vapor am vaporizing medium are,

released from the dried plastic, and recovering the plastic in the forni of a spongelike body.

6. A process for recovering solid polyiuerized styrol from solutions thereof which comprises preheating a solution of polymerized styrol. intel-mingling superheated steam therewith. distilling ott' the solvent while projerting the mixture under pressure through a constricted passage, and suddenly rcleasin" all. pressure at the end of the passage, allowing entrapped solvent vapor and steam to pass out of the dried styrol, and recovering the dried olymerized styrol in the form of a sponge-like body.

7. As a new product, a reticular mass of a substantially solvent and moisture free polymerized styrol.

8. As a new product, an easily crushed cellular mass of a dried polymerized styrol.

9. As a new product, an ex anded cellular and friable mass of a toug i, amorphous styroliolyu-ier.

10. n apparatus for removing solvent from solutions of solid materials comprising an inner supply pipe for the solution to be dried, an outer surrounding supply pipe for a heated gaseous drying agent, a lead having a constricted disc large passage adjacent. and aligned with the end of the said first pipe, and means whcrebythe drying agent may be inwardly and radially admitted to the solution rior to the entrance of the latter into the iscliarge passage.

11. An apparatus for removing solvent from solutions of solid materials comprising an inner supply pipe for the solution to be dried, an outer surrounding supply pipe for a. heated gaseous drying agent, a longitudinally adjustable cap mounted on said second pipe, and a nozzle member carried by said cap 1n alignment with said first pipe.

12. An apparatus for removing solvent from solutions of solid materials comprising an outer supply pipe for a, vaporizing medium, a cap mounted on the end of said pipe and having an inwardl extending nozzle member, an inner ipe or the solution to be dried disposed 1n alignment with said nozzle member, and means whereby the inner pi e and nozzle member may be relatively a just/ed.

Signed at New York, New York, this 8th day of June, 1927.

WILLIAM S. JOHNSTON.

Signed at New York, New York, this 8th day of June, 1927.

ALEXIS W. KEEN.

CERTIFICATE OF CORRECTION.

atent No. l, 673, 685.

Granted June l2, 1928, to

WILLIAM S. JOHNSTON ET AL.

lt is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Page l, line i4. tor the word "vaporized" read "yaporiziug"; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 14th day of August, A. D. 1928.

(Seal) M. J. Moore, Acting Commissioner of Patents.

the mixture into attenuated form while continuing the heating and pressure and suddenly releasing the pressure.

4. A proross for removing solvent from solutions of solid materials whirh romprises preheating said solution, mixing.lr therewith a. vaporlzing medium under pressure, va oriziug.r the solvent in the mixture while sti under pressure, and suddenly releasing the pressure on ihn` mixture.

5. A process for converting solutions of polyiuerized plastics into solid form which comprises preheating a solution of a. plastic, mixilnr a vaporizing medium therewith, distilhng oll the solvent while projecting thc mixture through a constricbed passa and suddenly releasing all pressure at t e und of the passage, whereupon entrapped solvent vapor am vaporizing medium are,

released from the dried plastic, and recovering the plastic in the forni of a spongelike body.

6. A process for recovering solid polyiuerized styrol from solutions thereof which comprises preheating a solution of polymerized styrol. intel-mingling superheated steam therewith. distilling ott' the solvent while projerting the mixture under pressure through a constricted passage, and suddenly rcleasin" all. pressure at the end of the passage, allowing entrapped solvent vapor and steam to pass out of the dried styrol, and recovering the dried olymerized styrol in the form of a sponge-like body.

7. As a new product, a reticular mass of a substantially solvent and moisture free polymerized styrol.

8. As a new product, an easily crushed cellular mass of a dried polymerized styrol.

9. As a new product, an ex anded cellular and friable mass of a toug i, amorphous styroliolyu-ier.

10. n apparatus for removing solvent from solutions of solid materials comprising an inner supply pipe for the solution to be dried, an outer surrounding supply pipe for a heated gaseous drying agent, a lead having a constricted disc large passage adjacent. and aligned with the end of the said first pipe, and means whcrebythe drying agent may be inwardly and radially admitted to the solution rior to the entrance of the latter into the iscliarge passage.

11. An apparatus for removing solvent from solutions of solid materials comprising an inner supply pipe for the solution to be dried, an outer surrounding supply pipe for a. heated gaseous drying agent, a longitudinally adjustable cap mounted on said second pipe, and a nozzle member carried by said cap 1n alignment with said first pipe.

12. An apparatus for removing solvent from solutions of solid materials comprising an outer supply pipe for a, vaporizing medium, a cap mounted on the end of said pipe and having an inwardl extending nozzle member, an inner ipe or the solution to be dried disposed 1n alignment with said nozzle member, and means whereby the inner pi e and nozzle member may be relatively a just/ed.

Signed at New York, New York, this 8th day of June, 1927.

WILLIAM S. JOHNSTON.

Signed at New York, New York, this 8th day of June, 1927.

ALEXIS W. KEEN.

CERTIFICATE OF CORRECTION.

atent No. l, 673, 685.

Granted June l2, 1928, to

WILLIAM S. JOHNSTON ET AL.

lt is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Page l, line i4. tor the word "vaporized" read "yaporiziug"; and that the said Letters Patent should be read with this correction therein that the same may conform to the record of the case in the Patent Office.

Signed and sealed this 14th day of August, A. D. 1928.

(Seal) M. J. Moore, Acting Commissioner of Patents. 

